The present invention relates generally to flow regulation apparatus, and more particularly, to a valve assembly adapted to permit substantially free flow through the valve in a first direction, while preventing flow through the valve in a second, opposite direction.
The numerous uses of one way flow valves are well recognized. Such valves are particularly useful in the medical field such as in the performing of medical infusions.
One of the requirements for such valves is that the valves must offer little resistance to fluid flow in one direction but will completely stop fluid flow in the opposite direction. Many prior art valves do not operate or will not fully open at low inlet pressures. Other prior art valves will have a tendency to leak. This tendency to leak increases as the back pressure acting on the valve is lowered acting on the valve.
Other requirements for such valves is that they must be able to be economically manufactured, light in weight, simple in construction, and easy to use. Many prior art valves require that extremely close mechanical tolerances be maintained to prevent back flow during the period in which the valves are closed. The requirement of very close tolerances results in a significant increase in the cost of manufacturing the valves.
An additional requirement of such valves is their ability to purge air. Many prior art valves such as those using a disc or plate for sealing, tend to trap air. This air needs to be purged before intravenous infusion to reduce the possibility of an embolism occurring in the patient.
Accordingly, a need exists for a valve assembly allowing fluid flow in a first direction and preventing fluid flow in a second, opposite direction which is economical to manufacture, easy to use, and can operate reliably, efficiently, and safely on a variety of fluids.